Thermal stabilization of polymers is carried out in several ways. Some of the important methods are by using additives which act as radical scavengers and/or decompose hydroperoxides which are formed by the reaction of oxygen and the polymers. It has been known that transition metal compounds, and in particular copper compounds along with alkali halides, are routinely used for stabilization of polymers, particularly polyamides or nylons and in some cases other polymers such as polyolefins. Mechanisms of stabilization in the literature suggest that these materials work by radical scavenging, decomposition of hydroperoxides and by reduction in oxygen uptake by the polymers. This action preserves the molecular weight of the polymer and also associated properties, which are impacted by either polymeric chain breakdown, formation of conjugated groups or by their branching/crosslinking, etc. Many of the copper compounds which are used, such as CuI, CuBr and CuCl, are added as bulk particles and then usually melt blended, or are added when the polymers are formed, such as during condensation polymerization of nylons at high temperature. The focus of the present invention is to provide the transition metal compounds in a form so that they are easy to blend with the polymers and form thermally stable compositions. Thermal stability allows these polymers to be used at elevated temperature applications without losing their mechanical, optical, electrical or other properties. In some cases these may also improve or impart flame retardant properties.